This application claims priority to German Patent Application No. 101 43 671.8 filed on Sep. 6, 2001, the disclosure of which is incorporated herein by reference.
The invention relates to a device for use with a carding, cleaning, or similar machine for textile material such as cotton, synthetic fibers or the like. The device is provided with, for example, at least one rotating sawtooth roller or pin roller to which a vacuum can be applied at cleaning locations on the roller. The low-pressure vacuum generated by a vacuum system is supplied, for example, by a main line and individual branch lines to the cleaning locations. In some machines, at least one of the suction lines on a main carding cylinder is under vacuum constantly.
In the device show in European Patent 0 750 059, waste material in the licker-in region is not removed continuously, but drops into a collection box arranged below the licker-in. This waste is then removed from the collection box periodically. As a result, no continuous vacuum is required in the region of the licker-in. The intermittent emptying of the collection box results in the suctioning effect in the region of the licker-in being limited to an extremely short time interval and does not significantly influence the loss of desirable fibers. In contrast, a continuous suctioning takes place at suctioning locations on the carding cylinder. For a carding machine where the low pressure generated by a central vacuum system is applied via a joint line to the cleaning locations, an intermittent actuation of a valve is used to empty the waste material collected in the collection box via a transfer line that connects the collection line to the collection box as well as the joint line. During the emptying of the collection box, the valve maintains a reduced low pressure at the cleaning locations. In the process, the pressure is reduced only briefly by the same amount at all cleaning locations on the main carding cylinder. In contrast, the cleaning locations are fully suctioned nearly all of the time. The high total amount of air required for removing the waste material is a disadvantage. Further, an increase in the number of cleaning locations, based on an increase in the requirements for production and quality, magnifies this problem. The amount of air required for removing the waste material consequently rises, leading to a high expenditure of energy and higher operating costs.
It is an object of the invention to create a device which avoids the aforementioned disadvantages and, in particular, reduces the total amount of air required for removing the waste material, especially for an increasing number of cleaning locations.
Particular embodiments of the invention provide a vacuum device for use with a textile processing machine having a rotating roller with cleaning locations. The device has a vacuum generator, a main vacuum line operatively associated with the vacuum generator, a plurality of individual vacuum lines, and a vacuum control valve having an upstream side and a downstream side, the upstream side being opposite the vacuum generator. Each of the individual vacuum lines is operatively associated with the main vacuum line and has at least one cleaning opening. Each of the cleaning openings is for positioning at one of the cleaning locations. The vacuum generator creates a first vacuum at the upstream side of the vacuum control valve when the vacuum control valve is in one operating position, and a second vacuum at the upstream side of the vacuum control valve when the vacuum control valve is in a second operating position. The second vacuum is stronger than the first vacuum.
Other embodiments of the invention provide a textile processing machine. The machine has a rotating roller with cleaning locations, and a vacuum device. The vacuum device has a vacuum generator, a main vacuum line operatively associated with the vacuum generator, a plurality of individual vacuum lines, and a vacuum control valve having an upstream side and a downstream side, the upstream side being opposite the vacuum generator. Each of the individual vacuum lines is operatively associated with the main vacuum line and has at least one cleaning opening. Each of the cleaning openings is positioned at one of the cleaning locations. The vacuum generator creates a first vacuum at the upstream side of the vacuum control valve when the vacuum control valve is in one operating position, and a second vacuum at the upstream side of the vacuum control valve when the vacuum control valve is in a second operating position. The second vacuum is stronger than the first vacuum.
The invention can reduce the total amount of air required for waste removal. Sufficient cleaning can be achieved if at least some of the cleaning locations on the main carding cylinder are not provided with constant full-strength vacuum. It is sufficient to use a relatively weak airflow (partial vacuum) for suctioning off undesirable dust, at least at certain cleaning locations. Using a partial vacuum at these cleaning locations permits the use of a full-strength vacuum during brief intervals to remove the collected waste material while providing an overall reduction in the amount of air required. The higher the number of cleaning locations, the stronger the effect of the partial vacuum, which further reduces the air and energy expenditure.
The vacuum control valve can switch between partial vacuum and full vacuum. The cleaning locations suction and store waste with a low vacuum during a particular time period. The stored waste material is suctioned out with a higher amount of air, but only during brief time intervals. The vacuum lines are preferably combined, at least in part, to form groups. The vacuum control valve is preferably provided with an arrangement of slide valves.